1. Field of the Invention
The present invention relates to a method of treating waste water discharged from medical facilities. More specifically, the present invention relates to an apparatus and method of treating pharmaceutical drugs included in waste water by means of electrolysis to the extent that the pharmacological activity and toxicity thereof are eliminated or reduced to an acceptable level.
2. Description of the Background Art
Nature including the river and ocean is affected in one way or another by the activities of humans. Usage of water supplied from rivers and oceans as well as sewerage releasing used water back to the rivers are critical factors in the environment. As to the issue of sewerage, the used water output from households, companies, plants and the like, i.e. waste water, should be restored as close as possible to the former state before being dispatched back to the rivers and oceans for environmental reasons. As such, various public and governmental regulations have been established. Presently, particular types of waste water are subjected to some treatment to a level so as not to effect the environment.
It is appreciated that waste water from hospitals and medical facilities is one of the factors of discharged hazardous substances. However, only those related to infectious waste are subject to the aforementioned regulations. Those related to noninfectious waste are just regulated as industrial waste under special supervision. In other words, there are some chemicals among noninfectious waste from hospitals and medical facilities that are released to the river without undergoing substantially any treatment. Such noninfectious waste includes harmful remnants such as injection needles and surgical knives as well as hazardous waste such as antiseptic solutions, antibiotics, antitumor agents and the like.
Such hazardous waste of antitumor agents, antiseptic solutions, antibiotics, and the like exhibit various properties of cytotoxicity, mutagenicity, teratogenicity and the like, killing biological organisms and bacteria as well as inducing damage on the gene level. If the waste is not treated to a level of eliminating or reducing the pharmacological activity before being discharged into the river, there is a possibility of the ecology and environment being adversely affected potentially.
Agents identified as such hazardous waste may not be metabolized in the human body, when applied to a human being, so that it will be excreted in the original form of the agent. No legal regulations are established at the current stage as to such agents included in excretion. The effect of such agents excreted from the human body on the ecological system and environment, when discharged to nature in an untreated form, is a matter of concern.
It is therefore necessary to apply some treatment on the waste fluid discharged from medical facilities to a level where the toxicity of the agent included in the waste is eliminated or reduced.
As to the current treatment of medical waste, mainly incineration is employed, as disclosed in Japanese Patent Laying-Open Nos. 2001-62437, 7-313584, 5-302706, and “Supervision Techniques of Hazardous Microbes”, Volume II, pp. 733-735. An evaporation concentration incineration method disclosed therein will be described hereinafter. As shown in FIG. 18, this method is a combination of evaporation concentration and incineration. The method includes the steps of condensing the waste water by distillation to increase the concentration of the organic matter, approaching the calorific value of 10,500 kJ/kg corresponding to hypergolic waste water, and then incinerated together with another waste fluid.
The initial expense to introduce the equipment for this method as well as the running cost thereof are extremely high. This method is not preferable for economic reasons. Furthermore, considerable energy is required for incineration and evaporation, and the energy efficiency is poor. There is also a problem that the discharged amount of carbon dioxide is great.
Additionally, a pretreatment of condensing and the like is required prior to incineration. The efficiency from the standpoint of time is also poor since the waste fluid must be transported from the medical facility to the incineration facility. Furthermore, the cost for transportation will be incurred.